Jack



FIG. 1 is a front perspective view of the jack showing our new design;

FIG. 2 is a front end elevational view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a rear end elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof.

The ornamental design for a jack, as shown and described.